A search engine is a computer program that helps a user to locate information. To locate information on a particular topic, a user can submit to a search engine one or more search query terms related to the topic. In response, the search engine executes the search query and generates information about the results of the search. The information about the results of the search, referred to herein as the “search results”, usually contains a list of the resources that satisfy the search query. The resources identified in the search results are referred to herein as “matching resources”.
While search engines may be applied in a variety of contexts, search engines are especially useful for locating resources that are accessible through the Internet. Resources may include files whose content is composed in a page description language such as Hypertext Markup Language (HTML). Such files are typically called pages. Using a web browser, pages may be retrieved by selecting HTML links that contain the Universal Resource Locators (URLs) of the pages.
Depending on the query terms used and the number of pages that contain those query terms, search results may contain so many matching resources that a user may be overwhelmed when trying to determine which matching resources to investigate further. To assist a user in selecting one or more matching resources from a list, the search results may include a short description, or abstract, for each matching resource. By reading the abstract for a given matching resource, a user should be able to better determine whether the matching resource merits further investigation. Abstracts should be relatively short, so that a user may quickly judge the relevance of matching resources listed in the search results.
Various efforts have been made to improve the content of the abstracts that are presented to users. For example, one technique to improve the content of abstracts is described in U.S. patent application Ser. No. 10/365,273, entitled “GENERATING DESCRIPTIONS OF MATCHING RESOURCES BASED ON THE KIND, QUALITY, AND RELEVANCE OF AVAILABLE SOURCES OF INFORMATION ABOUT THE MATCHING RESOURCES”, the contents of which are incorporated herein by reference. That application describes a technique for selecting the process which generates the abstract for a web page, from a plurality of available processes, based on the kind, quality, and relevance of the available sources of information about the page.
Another technique to improve the content of the abstracts is described in U.S. Pat. No. 6,711,567, entitled “DELIVERING NON-DEFAULT ITEMS IN ASSOCIATION WITH SEARCH RESULTS”, the contents of which are incorporated by this reference. The “NON-DEFAULT” patent describes a technique for delivering search results pages to the users of a search engine, where one or more search result listings on the search results pages include items that are not included by default. The non-default items may take many forms, including but not limited to images, banners, controls, animations, and even applets in the JAVA language. The non-default items may be designed to entice the search engine users to select the search result listing with which they are associated over possibly higher-ranked search result listings that contain only default items.
The party that controls a web site may be pleased if the use of non-default items in the search results entices more users to visit the web site. However, the search engine user's experience is not necessarily improved. Therefore, it is desirable to provide techniques for making the contents of search result listing more useful to a user, thereby facilitating the user's search for useful information.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.